This invention relates to novel lice-killing compositions for the control of lice on animals, primarily humans, and to methods of controlling lice on such animals.
Pediculosis capitis is one of the more common forms of pediculosis in humans due to investation with the head louse, Pediculus Humanus Humanus. Transmission of the lice is usually by personal contact or common use of brushes, combs, or headgear.
Pediculosis Captitis is a lice infestation characterized by itching and possibly eczematous dermatitis. In long standing, neglected cases, scratching may result in marked inflammation. Secondary infection by bacteria may occur with formation of pustules, crusts, and suppuratim. The hair may become matted and give rise to a disgusting odor.
Another form of pediculosis, known as Pediculosis Corporis or pediculous vestimenti, is an infestation with the body louse Pediculus Humanus Corporis. P. Corpus is transmitted by direct contact or use of infested wearing apparel that typically occurs as the result or crowding or unhygenic conditions. Symptoms include intense itching while, in particular, heavy infestations generalized red skin eruptions, mild fever, tiredness, irritability and possibly weakness and debility may occur.
A third type is pediculosis pubis and is due to body infestation with the crablouse, Phthirus Pubis which is generally confined to the hairs of the genital region, but the hair of the axilla, eyebrows, eyelashes, beard, and in hairy individuals, body surface may be involved. Lice may be acquired from direct contact with another infested individual, wearing contaminated clothing, from toilet seats, or from bed clothes. Symptoms include itching, especially in the genital or crural regions; small pale-blue spots resulting from the action of salivary secretion on hemoglobin are characteristic. See generally The Merck Manual, 12th Edition, Merck & Co., Inc., pp. 1455-1457 and 1633-1634 (1972).
There are several treatments now used for these conditions. An ectoparasiticide connotes only those drugs that are used against the animal parasites; in the human these are categorized as primarily mitocides, such as for the treatment of scabies, a mite infestation; or pediculocides, for the treatment of lice. Previously proposed chemical treatments include the use of chlorophenothane (DDT) and gamma benzene hexachloride (Kwell), as the major ectoparasiticides. Also benzyl benzoate, pyrethrins, malathion, a combination of tetrahydronaphthalene and cupric oleate (Cuprex), isoboruyl thiocyanoacetate, sulfur ointment U.S.P. and sulfurated lime have been used. The use of each of these materials has been questioned as to precautions and potential adverse responses and/or effectiveness; see Goodman and Gilman, The Pharmacological Basis of Therapeutics, 5th Edition, pp. 1012-1015 (1975).
Other forms of treatment are physical in nature and include removal of the hair-infested areas in question, followed by washing with strong soap and optionally one of the ectoparasiticides listed above. Clothing or instruments in contact with the affected body parts are also to be sterilized, such as by dry heat (140.degree. F. for five minutes), hot water (150.degree. F. for five minutes) or dry cleaning.
Lice infestation is a world-wide and growing concern, particularly in recent years in the United States among primary school students, and is often embarrassing as it was previously associated only with overcrowded conditions where inadequate facilities for personal hygiene or clean clothing exist. Pediculocides previously employed have now come under more careful examination and review and certain of the more commonly used materials, such as DDT and malathion, may be or have been discontinued. A need remains for a safe yet thoroughly effective pediculocide composition useful for animals, particularly humans.